Question: Solve for $y$ : $-13 = y + 3$
Subtract $3$ from both sides: $ \begin{eqnarray} \\ \hphantom{-13 {- 3}} &\hphantom{=}& \hphantom{y} \\ -13 &=& y + 3 \\ \\ {-3} && {-3} \\ \end{eqnarray} $ $ \begin{eqnarray} \\ -13 {- 3} &=& y \\ \end{eqnarray} $ Simplify. $ y = -16$